The Collaborative International Dictionary of English v.0.48:

Flower \Flow"er\ (flou"[~e]r), n. [OE. flour, OF. flour, flur,
   flor, F. fleur, fr. L. flos, floris. Cf. Blossom,
   Effloresce, Floret, Florid, Florin, Flour,
   Flourish.]
   1. In the popular sense, the bloom or blossom of a plant; the
      showy portion, usually of a different color, shape, and
      texture from the foliage.
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   2. (Bot.) That part of a plant destined to produce seed, and
      hence including one or both of the sexual organs; an organ
      or combination of the organs of reproduction, whether
      inclosed by a circle of foliar parts or not. A complete
      flower consists of two essential parts, the stamens and
      the pistil, and two floral envelopes, the corolla and
      callyx. In mosses the flowers consist of a few special
      leaves surrounding or subtending organs called archegonia.
      See Blossom, and Corolla.
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   Note: If we examine a common flower, such for instance as a
         geranium, we shall find that it consists of: First, an
         outer envelope or calyx, sometimes tubular, sometimes
         consisting of separate leaves called sepals; secondly,
         an inner envelope or corolla, which is generally more
         or less colored, and which, like the calyx, is
         sometimes tubular, sometimes composed of separate
         leaves called petals; thirdly, one or more stamens,
         consisting of a stalk or filament and a head or anther,
         in which the pollen is produced; and fourthly, a
         pistil, which is situated in the center of the flower,
         and consists generally of three principal parts; one or
         more compartments at the base, each containing one or
         more seeds; the stalk or style; and the stigma, which
         in many familiar instances forms a small head, at the
         top of the style or ovary, and to which the pollen must
         find its way in order to fertilize the flower. --Sir J.
         Lubbock.
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   3. The fairest, freshest, and choicest part of anything; as,
      the flower of an army, or of a family; the state or time
      of freshness and bloom; as, the flower of life, that is,
      youth.
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            The choice and flower of all things profitable the
            Psalms do more briefly contain.       --Hooker.
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            The flower of the chivalry of all Spain. --Southey.
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            A simple maiden in her flower
            Is worth a hundred coats of arms.     --Tennyson.
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   4. Grain pulverized; meal; flour. [Obs.]
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            The flowers of grains, mixed with water, will make a
            sort of glue.                         --Arbuthnot.
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   5. pl. (Old Chem.) A substance in the form of a powder,
      especially when condensed from sublimation; as, the
      flowers of sulphur.
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   6. A figure of speech; an ornament of style.
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   7. pl. (Print.) Ornamental type used chiefly for borders
      around pages, cards, etc. --W. Savage.
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   8. pl. Menstrual discharges. --Lev. xv. 24.
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   Animal flower (Zool.) See under Animal.

   Cut flowers, flowers cut from the stalk, as for making a
      bouquet.

   Flower bed, a plat in a garden for the cultivation of
      flowers.

   Flower beetle (Zool.), any beetle which feeds upon flowers,
      esp. any one of numerous small species of the genus
      Meligethes, family Nitidulid[ae], some of which are
      injurious to crops.

   Flower bird (Zool.), an Australian bird of the genus
      Anthornis, allied to the honey eaters.

   Flower bud, an unopened flower.

   Flower clock, an assemblage of flowers which open and close
      at different hours of the day, thus indicating the time.


   Flower head (Bot.), a compound flower in which all the
      florets are sessile on their receptacle, as in the case of
      the daisy.

   Flower pecker (Zool.), one of a family (Dic[ae]id[ae]) of
      small Indian and Australian birds. They resemble humming
      birds in habits.

   Flower piece.
      (a) A table ornament made of cut flowers.
      (b) (Fine Arts) A picture of flowers.

   Flower stalk (Bot.), the peduncle of a plant, or the stem
      that supports the flower or fructification.
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The Collaborative International Dictionary of English v.0.48:

Flower \Flow"er\ (flou"[~e]r), v. i. [imp. & p. p. Flowered
   (flou"[~e]rd); p. pr. & vb. n. Flowering.] [From the noun.
   Cf. Flourish.]
   1. To blossom; to bloom; to expand the petals, as a plant; to
      produce flowers; as, this plant flowers in June.
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   2. To come into the finest or fairest condition.
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            Their lusty and flowering age.        --Robynson
                                                  (More's
                                                  Utopia).
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            When flowered my youthful spring.     --Spenser.
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   3. To froth; to ferment gently, as new beer.
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            That beer did flower a little.        --Bacon.
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   4. To come off as flowers by sublimation. [Obs.]
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            Observations which have flowered off. --Milton.
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The Collaborative International Dictionary of English v.0.48:

Flower \Flow"er\, v. t.
   To embellish with flowers; to adorn with imitated flowers;
   as, flowered silk.
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WordNet (r) 3.0 (2006):

flower
    n 1: a plant cultivated for its blooms or blossoms
    2: reproductive organ of angiosperm plants especially one having
       showy or colorful parts [syn: flower, bloom, blossom]
    3: the period of greatest prosperity or productivity [syn:
       flower, prime, peak, heyday, bloom, blossom,
       efflorescence, flush]
    v 1: produce or yield flowers; "The cherry tree bloomed" [syn:
         bloom, blossom, flower]

Moby Thesaurus II by Grady Ward, 1.0:

296 Moby Thesaurus words for "flower":
   Chinese lantern, Christmas rose, Eglantine, acacia, advance,
   androecium, anther, arrowhead, asiaticism, aster, attain majority,
   axiom, azalea, batten, bead, bear fruit, bejewel, beribbon,
   bespangle, best, bleeding heart, bloom, blossom, blow, bluebell,
   boom, broom, bud, budding, burgeon, burgeoning, buttercup, cactus,
   calendula, calyx, camellia, carnation, carpel, center, champion,
   choice, chosen, chrysanthemum, cineraria, clematis, clethra,
   cockscomb, columbine, come of age, come out, come to maturity,
   core, cornel, cornflower, corolla, corolla tube, corona, cosmos,
   cowslip, cream, crocus, cyclamen, daffodil, dahlia, daisy,
   dandelion, delphinium, develop, device, diamond, dogwood, duckweed,
   edelweiss, effloresce, efflorescence, elect, elite, elixir,
   engrave, epicalyx, essence, essential, euphuism, evolute, evolve,
   fat, fatten, feather, figurative language, figurativeness, figure,
   figure of speech, filigree, finest, flag, flax, fledge,
   fleur-de-lis, floret, floriculture, floridity, floscule, flounce,
   flourish, floweret, flowery style, focus, forget-me-not, forsythia,
   foxglove, foxtail, fuchsia, fundamental, gardenia, gardening,
   garland, gem, gentility, gentry, geranium, germination, gist,
   gravamen, groundsel, grow, grow fat, grow up, growth, gynoecium,
   hawthorn, heart, heather, hibiscus, honeysuckle, horehound,
   horticulture, hortorium, hyacinth, hydrangea, hypostasis,
   illuminate, image, imagery, impatience, indigo, inner essence,
   iris, jasmine, jewel, jonquil, kernel, lavender, leave the nest,
   lilac, lily, lobelia, lotus, lupine, luxuriation, magnolia, mallow,
   manner of speaking, marigold, marrow, marsh marigold, marshmallow,
   maturate, mature, mayflower, meat, megasporophyll, mellow,
   microsporophyll, mignonette, moccasin flower, mock orange,
   monkshood, motherwort, myrtle, narcissus, nonesuch, nonliterality,
   nonliteralness, nonpareil, nub, nucleus, nuts and bolts, oleander,
   open, optimum, orchid, ornament, oxalis, paint, pansy, paragon,
   peony, perianth, periwinkle, petal, phlox, pick, pink, pistil,
   pith, plume, poppy, postulate, posy, pride, prime, primrose,
   principle, prize, progress, pullulation, purple passage, quality,
   queen, quid, quiddity, quintessence, ranunculus, reach manhood,
   reach twenty-one, reach voting age, receptacle, resurrection plant,
   rhododendron, ribbon, ripen, rose, sap, season, select,
   settle down, shoot, shooting star, snapdragon, snowball, snowberry,
   snowdrop, society, soul, spangle, spiraea, spirit, spray,
   sprouting, stamen, stigma, stock, strawflower, stuff, style,
   substance, sunflower, superlative, sweet William, sweet alyssum,
   sweet pea, temper, the best, the best ever, the nitty-gritty,
   the tops, the very best, thrive, tinsel, toga virilis, top, torus,
   trillium, trope, tulip, turn of expression, umbrella plant, unfold,
   upper class, upper crust, vegetation, verbena, vetch, viola,
   violet, wallflower, water lily, wax, way of speaking, wildflower,
   wisteria, wolfbane, wreathe, yarrow, yucca, zinnia